Re: [ patch 00/21 ] support multiple, pending ddebugs at kernel-boot

From: Bart Van Assche
Date: Tue Jul 12 2011 - 01:53:35 EST


On Mon, Jul 11, 2011 at 9:06 PM, Jim Cromie <jim.cromie@xxxxxxxxx> wrote:
> On Mon, Jul 11, 2011 at 12:30 PM, Bart Van Assche <bvanassche@xxxxxxx> wrote:
>> As far as I can see with v2 of this patch set a query gets on the
>> pending list if either +a has been specified or no matches were found
>> the first time a query is run. Are both mechanisms necessary ? If not,
>> I propose to leave out the second. That will not only allow to
>> simplify the code somewhat but will also reduce confusion for
>> dynamic_printk users.
>>
>
> Both conditions are necessary:
> - 'a' flag required,
> - query not directly applicable.
>
> root@voyage:~# echo "module nosuch +p" > /dbg/dynamic_debug/control
> root@voyage:~# cat /sys/module/dynamic_debug/parameters/pending_ct
> 0
>
> root@voyage:~# echo "module nosuch +ap" > /dbg/dynamic_debug/control
> root@voyage:~# cat /sys/module/dynamic_debug/parameters/pending_ct
> 1

The above example contradicts the following code added in patch 09/21:

/* actually go and implement the change */
nfound = ddebug_change(&query, flags, mask);
+
+ pr_info("nfound %d on %s\n", nfound, show_ddebug_query(&query));
+ if (!nfound)
+ return ddebug_save_pending(&query, flags, mask);
+
return 0;

Bart.
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